Warmup RESIBOX-3 Plug and Play Outdoor Controller

Warmup Resibox-3 Plug and Play Outdoor Controller

Plug-and-Play outdoor controller with 4 x 30A/2pole contactors. 100-277V rated with GFEP built-in protection.

Contactors allowing for a total load of 120A with a minimum power supply of 36A. Comes in LED enclosure, built-in Digital controller and ground temperature sensor.

– AIRSense sold separately.

Plug-and-Play outdoor controller with 4 x 50A/3pole contactors. 100-600V rated with GFEP built-in protection. AirSense sold separately.

RESIBOX-3 (RESIBOX-120) AND COMMBOX-600 The COMMBOX-600 is a “Plug and Play” controlled power distribution panel for frost protection, ice and snow melting applications.

When receiving a signal from the snow sensor/s (such as the AIRsense), it activates the contactors, energizing the heating elements.

Based on the DIP switches configuration, the zones are activated either continuously or in customized sequencing between the zones. The adjustable Hold-On timer keeps the outputs to the zones active, to ensure complete snow melting.


  • Automatic Power/Load Distribution
  • Up to 5 zones, 600A
  • GFEP Protection Built-in
  • Sequencing allows sharing of minimum required power supply
  • Multiple Snow Sensor inputs
  • User-friendly interface
  • Integrated Electronic Controller with back-lit display
  • Energy Efficient Algorithm
  • ETL approved with UL approved components.


Approvals – ETL Listed CAN/CSA-C22.2 No. 14 | UL-508A
Enclosure Protection – IP20, Indoor Mounting
Dimensions – 18x18x8 inch (50x50x25 cm)
Equipment Protection – (default 0.2A)
GFS – Adjustable time delay 0.1-1 sec. (default 0.1 sec.)
Manual Reset GFS – Push button on Front Panel
Four Satellite – 600 VACS, 50 A Max
Contactors – (Resistive), 50/60 Hz, 3-Poles
One Satellite – 277 VAC, 30 A Max (Resistive)
Contactor – 50/60 Hz, 1-Pole 600 VAC / 50 A per pole
Terminal blocks – 6 mm2 ,10 AWG (max)


  • Temperature set point
  • Lower ambient temperature limit
  • Slab Upper Temperature Limit to deactivate heaters for Energy Efficiency
  • Time delay (Hold-on) before deactivating the heaters
  • ON time for Manual mode
  • DIP Switches located on the controllers provide easy access to technician mode and to the system configuration settings.
  • A 5th output (277 VAC, 30A Max Single Phase) can be used as a stand-alone ice melting zone or be activated simultaneously with zone #4. The Zone #5 offers a simple option for gutter, roof ice-melting or critical zone.
  • The COMMBOX-600 allows snow sensor input both from the sensors and also from a 3rd party snow sensors.
  • Heaters cycle time / Splitting time between zones
  • Number of zones and sequence of operation (Sensors and heaters control logic)
  • Snow sensor RH sensitivity
  • Number of snow sensors connected
  • 3 terminals in the COMMBOX-600 are available to connect a CIT-1???, GIT-1??? or SIT-6E??? sensors and use them to control some or all of the zones.
  • Installing the system is a quick and easy task. Apart of mounting the metal box to the wall, the installer needs only to connect the line in and line out wires in the marked terminals and the system is ready to work.


For effective and energy efficient snow melting installations, Warmup?? does not recommend heating in more than two zones.


Will any third party sensor work with the CommBox or ResiBox?

The CommBox and Resibox have been programmed to work with a variety of third-party sensors.Though Warmup may not be familiar with all the 5 and 6-signal sensors on the market, the basic functioning are similar.

Sensors from Environmental Technologies Inc (ETI) have been tested and perform well. As an example, the GIT-1 and CIT-1 sensors are compatible with the Warmup system. They can even be connected in conjunction with the AirSense sensor from Warmup.

Where are the DIP switches located on the COMMBOX-600?

The four DIP switches are located on the back of the Commbox thermostat unit, on the back of the door. Please follow the instruction manual for proper use.

What Does the HI/LO Error message mean on my COMMBOX?

The HI/LO error message means that the ambient sensor readings (on snow sensor) are out of reliable measuring range. HI LO

Ambient Temperature < -9??F – Ambient Temperature > 54??F

The system will continue to operate using constant predefined values. In addition, the display will alternate between ???LO??? and -11??F for low temperature readings, and between ???HI??? and 55??F for high temperature readings.

What does COMMBOX error code “SensErr 2” mean?

Error 2 ???SensErr 2??? will appear when the upper limit sensor is not connected or has short-circuited.

The system will continue to operate regardless of the upper limit temperature.

Required Actions:

1. Refer to P03 section of the technician settings.
2. Check the temperature value and disable the sensor if needed.
3. Replace the sensor.

What does COMMBOX error code ???SensErr 1??? mean?

Error 1 ???SensErr 1??? will appear when there is a communication error with one (or more) snow sensors.

If the system is configured to work with more than 1 snow sensor, the faulty snow sensor number will appear on display: P01, P02, P03 or P04.

The system will use readings from snow sensor 1 instead of the missing readings from the faulty snow sensor.

How many Mats or Amps can I connect to the CommBox?

The CommBox-600 is equipped with four (4) 50Amp 3-Phase relay contactors. This means that at 2-phase, you can connect up to 200 Amps worth of power, but at 3-phase, you can connect 150A per contactor. The relays are rated for 120-600 volts so the CommBox can be wired for 208, 277 and 480 using 3-Phase.

How long should I program my CommBox to melt snow?

It will vary depending on the depth of the cable in the material (concrete, pavers or asphalt) and the voltage input into the cable (280-240-277). The lower the cable is embedded and the lower the voltage, the longer the system will have to run.

It is clear that pre-runs and anticipation of the snowfall is critical for a successful system. In the event of high precipitation, manually activating the system several hours prior is recommended, as it will actually reduce the total run-time as melting will occur faster by preventing build-up. When snow has had the chance to build up, it takes significantly longer to melt it.

Two hour run times per zone is typical. Make sure that zone 1 (contactor 1) is the most critical area (such as a walkway to the door or tire-tracks) as zones 2 and following will experience build-ups and take longer to heat up.

Please refer to the installation manual for more information.

Warmup RESIBOX-120 Specifications and installation


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